Flux noise in particulate media: Measurement and interpretation

Flux noise in a magnetic recording medium refers to media noise prior to the shaping of its spectral content by the spatial response of the head and channel. The spectral content of such noise has been measured in two particulate media exhibiting little excess noise due to incomplete dispersion and surface roughness. In the absence of these effects the influence of other types of particle-particle correlations may be inferred from the flux noise spectra. The experimental spectra showed an exponential dependence on the wavenumber reflecting such correlations. A microscopic model of the media incorporating physical chaining of individual particles was found to explain the experimental spectra.